It was one of the biggest head-scratchers in TV: how in the heck did Carrie Bradshaw manage to live the life of a Manhattan millionaire on a single weekly newspaper column?

With nary a trust fund nor sugar daddy to rely on, Bradshaw managed to rack up a $40,000 shoe debt, yet still managed to buy her own apartment, and still have all the time (and cash) in the world for Cosmos and brunches.

Well, according to new numbers crunched by finance company Giffgaff Gameplan, Carrie's dream life was very much that - a dream. Recruiter James Calder estimated the girls' salaries over the years versus their spending habits. He calculated that not one of them ended the five series less than $100k in debt. Were they real women with real-life bank accounts, Samantha Jones would have ended up, says Calder, the worst off of the four, a good $774,000 (€678,000) in the red by the end of five seasons.

Closer to home, 38-year-old Dubliner Cliona Walsh (not her real name), who works in advertising, fully bought into a similar carefree ideal. Around the zenith of the Celtic Tiger, she enjoyed spending much of her disposable income (and then some) on enjoying the sort of gilded lifestyle that she felt she had worked hard for.

"My sense of it was, 'everyone else is at this'," she recalls. "There was an app that totted up how much money I'd spent on drink in my lifetime and it was something ridiculous like €60,000. Little did I know that a lot of my friends were going home and making sure that their own books were balanced. I kept getting those letters saying I was overdrawn, and that I was paying an extra few quid a month because of it.

"I knew I might have been reaching a tipping point when I could tell you my four credit card numbers from memory," she says. "Online shopping only ever took about two minutes, which is a dangerous game."

Carrie Bradshaw and her girlfriends spent money in Sex And The City like there was no tomorrow

And while the figures weren't quite as dizzying as Carrie & Co, Cliona soon managed to ratchet up a sizeable credit card debt to the tune of about €17,000.

"I was paying a minimum every month by standing order, but to be honest, it barely put a dent in it," she admits. "The statements would arrive to the house and just go straight into 'filing'. Initially, I was putting €400 a month on it to get it down, but it did mean having to freeze my pension payments for a bit."

Debt and the thirty-something lifestyle isn't quite what it once was, and a perfect storm of factors has led to a time-bomb.

Thirty-somethings are staying younger for longer, for a start, and that means they're 'spending' younger for longer.

Many are living at home, holding off on marriage and families for longer, eschewing (and ghosting on) unfulfilling jobs, and not showing much interest in building up their credit scores.

It's the generation, too, that came of age during the Celtic Tiger - a time when hearty consumption was less the exception and more the rule. A decade on and they are certainly no strangers to zero-hour contracts, the precarious gig economy and spiralling rents.

Those who have given up the dream of owning their own property have switched lanes, spending their money on an Insta-ready lifestyle.

"There's a very fine line between aspiration and accepting reality," asserts financial expert John Lowe, AKA The Money Doctor. "Not everyone is going to be a millionaire. At the start of your adult life, things are fun and you're having holidays and parties every night and the odd lock-in. It takes a while for reality to creep in."

And given the nature of the economy, many thought they'd be able to access a certain amount of disposable income, or a certain lifestyle by a certain age, and are only too willing to stick it on the credit card in order to make that lifestyle their reality.

"Feeling the pressure to succeed and to have achieved everything by your 30s is something I come across a lot in the therapy room," admits Sharron Grainger, psychologist at the Connolly Counselling Centre in Stillorgan. "If only these clients could remember that life is not a race."

"There's definitely a real sense that life is short, and people should be having fun while they can," agrees Lowe. "One guy came into me doing an assessment about finance and he revealed he buys three lattes a day. I told him that when he added it up, it was around €2,000 a year, but he said, 'I don't care. It's the only way I can go through the day'. I think people have to be aware that there may come a time in the future when they might have other priorities, like marriage or family."

Those in debt, says, Lowe, would do well to confront the brevity of the situation first and foremost, and then open up a dialogue with various lenders instead of ignoring the problem.

"People do need to get professional advice, and that advice will tell them that when you're in a hole, you need to stop digging," he says. "Stop borrowing. The key thing is, don't ignore [lenders'] letters. You need to communicate with them at all times, and if there's a problem, like being laid off or not getting a bonus, you need to put in a pre-emptive call.

"Find a credit card company that will give you six months' interest-free credit on balance transfer, and if you pay €200 a month for however many months, you get your card back.

"It really helps to track your spending over a four to five week period [Lowe has one, The Money Doctor, on the App and Play stores] - it's not unusual to go to an ATM, take out €400 and not have a breeze where it went," he adds. "You can still buy lattes, but if you want to save something at the end of the month, it's important to find out how much it really costs you to live."